Smell, taste, whatever. It shouldn't be anywhere near your face. I've NEVER had to deal with that problem. You'd have to be blowing the air directly into a wall, instead of over the top of a surface like you're supposed to, for any of it to blow back into your face. Or maybe you have a fan running that's blowing air directly back at you, which is also something that shouldn't be happening while you're using this stuff.